Surgical instrument

ABSTRACT

A cannulated retrograde reamer that is adjustable to create tunnels of multiple different diameters. The cannulated retrograde reamer substantially reduces the risk of tunnel malposition and/or misalignment, and can be adjusted to create a range of tunnel diameters, thereby allowing inventory levels to be reduced for a surgical case.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims benefit of the priority of U.S. ProvisionalPatent Application No. 61/733,479 filed Dec. 5, 2012 entitled SURGICALINSTRUMENT, and U.S. Provisional Patent Application No. 61/757,843 filedJan. 29, 2013 entitled SURGICAL INSTRUMENT.

TECHNICAL FIELD

The present application relates generally to surgical instruments, andmore specifically to surgical instruments having at least one cuttingmember, such as a rotatable blade for use in retrograde cutting of bone.

BACKGROUND

Some surgeons have performed anterior cruciate ligament (ACL) surgeryusing a retrograde approach to create the femoral ACL tunnels (i.e.,“All-inside ACL Reconstruction”). As illustrated in FIG. 1 , thisapproach typically requires a surgical instrument 100 that can drill atunnel 102 in a retrograde fashion, as the surgeon pulls-back (seedirectional arrow 108) on the retrograde reamer 104 from a bone jointspace 106 towards the lateral femoral cortex. However, such a surgicalinstrument tends to create a tunnel that is not truly circular, orworse, the tunnel can be created along a pathway that diverges from theintended trajectory, and thus may not be anatomic and/or may causeinjury to neurovascular structures, etc. In addition, such a surgicalinstrument is generally specific for creating tunnels of a certain fixeddiameter, which requires having access to a large inventory ofinstruments for one surgical case.

Moreover, surgeons who conduct ACL reconstruction generally prefer tomimic the natural anatomy to achieve optimal results. The placement of atendon graft in the original footprint of the ACL is generally referredto as “anatomic ACL reconstruction”. One feature of anatomic ACLreconstruction is the proper placement of the tunnels for the tendongraft. The tunnel exit in the space of the bone joint should be accurateto ensure the functionality of the graft. Further, the tunnel exit onthe lateral side of the femur (thigh) should be appropriately placed toensure adequate tunnel length. It would be desirable to have improvedsurgical instruments that can assist the surgeon in the proper placementof the femoral tunnel.

SUMMARY

In accordance with the present application, a retrograde reamer isdisclosed that is adjustable to create tunnels of multiple differentdiameters. In one aspect, the disclosed retrograde reamer is cannulated.In another aspect, the disclosed retrograde reamer is configured tocreate tunnels having distinct stepped diameters. In still anotheraspect, the disclosed retrograde reamer includes at least one cuttingmember, and a mechanism operative to gradually move the cutting memberfrom a deployed position to a stored, closed, or collapsed position tocreate a tapered tunnel. The mechanism can be linked to rotations of thecutting member so that, for predetermined numbers of rotations, thecutting member moves specified distances toward the stored, closed, orcollapsed position.

In a further aspect, the disclosed retrograde reamer includes a firsttubular shaft having a sidewall, which includes at least one openingtherethrough. The retrograde reamer further includes a second shaftmovably disposed within the first tubular shaft, and at least onecutting member movably disposed in the first tubular shaft. The cuttingmember is operative, in response to the second shaft moving from a firstposition to a second position within the first tubular shaft, to movethrough the opening to an outside position that is at least partiallyoutside the first tubular shaft, thereby defining a cutting diameter.

The disclosed cannulated retrograde reamer can be configured toaccommodate a guide wire. Further, the cannulated retrograde reamersubstantially reduces the risk of tunnel malposition and/ormisalignment, and can be adjusted to create a range of tunnel diameters,thereby allowing inventory levels to be reduced for a surgical case.

Other features, functions, and aspects of the invention will be evidentfrom the Detailed Description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate one or more embodiments describedherein and, together with the Detailed Description, explain theseembodiments. In the drawings:

FIG. 1 is a diagram of a conventional surgical instrument configured todrill tunnels through bone in a retrograde fashion;

FIG. 2 is an illustration of an exemplary surgical instrument (alsoreferred to herein as the “retrograde reamer”) configured to drilltunnels through bone in a retrograde fashion, in accordance with thepresent application;

FIGS. 3 a-3 c depict diagrams of a first illustrative example of use ofthe retrograde reamer of FIG. 2 ;

FIG. 4 depicts diagrams of a second illustrative example of use of theretrograde reamer of FIG. 2 ;

FIG. 5 depicts diagrams of a third illustrative example of use of theretrograde reamer of FIG. 2 ;

FIG. 6 illustrates a plurality of alternative embodiments of theretrograde reamer of FIG. 2 ;

FIGS. 7 a and 7 b illustrate a first alternative embodiment of theretrograde reamer of FIG. 2 ;

FIGS. 8 a and 8 b illustrate a second alternative embodiment of theretrograde reamer of FIG. 2 ;

FIGS. 9 a and 9 b illustrate a third alternative embodiment of theretrograde reamer of FIG. 2 ;

FIGS. 10 a and 10 b illustrate a fourth alternative embodiment of theretrograde reamer of FIG. 2 ;

FIGS. 11 a and 11 b illustrate a fifth alternative embodiment of theretrograde reamer of FIG. 2 ;

FIGS. 12 a and 12 b illustrate a sixth alternative embodiment of theretrograde reamer of FIG. 2 ;

FIGS. 13 a and 13 b illustrate a seventh alternative embodiment of theretrograde reamer of FIG. 2 ;

FIG. 14 illustrates an eighth alternative embodiment of the retrogradereamer of FIG. 2 ; and

FIGS. 15 a-15 c illustrate a ninth alternative embodiment of theretrograde reamer of FIG. 2 .

DETAILED DESCRIPTION

The disclosures of U.S. Provisional Patent Application No. 61/733,479filed Dec. 5, 2012 entitled SURGICAL INSTRUMENT, and U.S. ProvisionalPatent Application No. 61/757,843 filed Jan. 29, 2013 entitled SURGICALINSTRUMENT, are hereby incorporated herein by reference in theirentirety.

With reference to FIG. 2 , an illustrative embodiment of components ofan exemplary surgical instrument 200 (also referred to herein as the“retrograde reamer”) is disclosed, in accordance with the presentapplication. As shown in FIG. 2 , the components of the retrogradereamer 200 include an elongated inner shaft 206, an elongated outertubular shaft 205, and a plurality of cutting members 204 movablycoupled to the elongated outer tubular shaft 205. The outer tubularshaft 205 includes internal threads at a distal end 207 thereof. Theplurality of cutting members 204 (e.g., two (2) cutting members) arelocated near the distal end 207 of the outer tubular shaft 205. Theinner shaft 206 includes an externally threaded distal tip 202.

When the retrograde reamer 200 is assembled, the inner shaft 206 isrotationally mounted within the elongated outer tubular shaft 205 suchthat the threaded distal tip 202 is engaged with the internal threads atthe distal end 207 of the outer tubular shaft 205. To deploy and actuatethe cutting members 204, the inner shaft 206 is rotated repeatedly(i.e., multiple revolutions), thereby causing the distal end 207 of theouter tubular shaft 205 to move toward a proximal end of the outertubular shaft 205. As the inner shaft 206 turns and the distal end 207of the outer tubular shaft 205 moves proximally, the two (2) cuttingmembers 204 near the distal end 207 of the outer tubular shaft 205 flexand expand outwardly, creating a progressively increasing cuttingdiameter. Once the cutting members 204 have reached a desired position,the relative positions of the inner shaft 206 and the outer tubularshaft 205 can be locked. The retrograde reamer 200 can then be rotated(such as by a drill) to create a retrograde tunnel having a desireddiameter.

To remove the retrograde reamer 200 from a bone joint after tunnelcreation, the inner shaft 206 is rotated in the opposite direction,thereby causing the distal end 207 of the outer tubular shaft 205 tomove distally, and the cutting members 204 to flex back, and close orcollapse to their pre-deployment (i.e., flat) configuration. Once thecutting members 204 have returned to their pre-deployment configuration,the retrograde reamer 200 can be removed from the surgical site.

It is noted that two or more cutting members like the cutting members204 may be provided. For example, three, four, five, six, or any othersuitable number of cutting members may be incorporated in the retrogradereamer 200. Further, the cutting members 204 may be hinged, and/or mayhave sharpened edges. The sharpened edges may be coated with a metal ormetal alloy, or diamond-like carbon to enhance strength and cuttingperformance.

It is further noted that the inner shaft 206 can be cannulated toaccommodate a guide wire. The retrograde reamer 200 may also beconnected to suction means so that cut tissue can be aspirated from thesurgical site through the cannulated inner shaft 206. The inner shaft206 could also include a handle with a counter that could indicate thecurrent tunnel diameter as a function of the number of shaftrevolutions. The mechanical force generated during retraction/closure ofthe cutting members 204 after tunnel creation can be made to overcomethe resistance of any residual tissue caught in the cutting members 204.The presence of such residual tissue is a frequent nuisance ofconventional retrograde reamers.

In addition, the inner shaft 206 can be replaced with a shaft that isconnected to the distal end 207 of the outer tubular shaft 205 to enablecontrol of cutter deployment by a ratchet-locking system, or any othersuitable locking mechanism. The locking mechanism can be located at aproximal end of the retrograde reamer 200. The ratchet-locking systemcan be configured to adjust the cutting diameter of the cutting members204 by ratcheting in either direction. The axial position of the innershaft 206 can be locked (e.g., by teeth) at the desired cuttingdiameter. When engaged, such teeth can prevent the inner shaft 206 frommoving. When disengaged, the inner shaft 206 is movable. Movement of theinner shaft 206 in a proximal direction activates the cutting members204 and increases the cutting diameter. Movement of the inner shaft 206in a distal direction decreases the cutting diameter and effectivelydeactivates the cutting members 204. In some embodiments, the lockingmechanism may be configured to be similar to a cable tie.

The disclosed surgical instrument will be further understood withreference to the following illustrative examples. In a firstillustrative example, as described with reference to steps 1-7 of FIG. 3a , a retrograde reamer, such as a 2.4 mm retrograde reamer 316, isemployed in conjunction with a 4.5 mm reamer. As depicted in step 1 (seeFIG. 3 a ), a 2.4 mm guide wire 302 is drilled into a bone joint 304using a suitable drill 306, bullet 308, and guide 310. As depicted instep 2, the bullet 308, the guide 310, and the drill 306 are removed. Asdepicted in step 3, a 4.5 mm reamer 312 is drilled over the guide wire302 using a suitable drill 314. As depicted in step 4, the drill 314 andthe 2.4 mm guide wire 302 are removed. As depicted in step 5, the 2.4 mmretrograde reamer 316 is inserted into the 4.5 mm reamer 312. Forexample, the 2.4 mm retrograde reamer 316 can extend out of a distal endof the 4.5 mm reamer 312, or extend through windows in the 4.5 mm reamer312. As depicted in step 6, a cutting member 318 of the 2.4 mmretrograde reamer 316 is deployed. As depicted in step 7, after the 2.4mm retrograde reamer 316 is used to retro-ream a tunnel 320 through thebone joint 304, the cutting member 318 is closed or collapsed, and thesurgical instrument system is removed, FIG. 3 b depicts an alternativeto step 4 of FIG. 3 a , in which only the 2.4 mm guide wire 302 isremoved, and the 2.4 mm retrograde reamer 316 is inserted through theback end of the drill 314.

With further regard to the first illustrative example. FIG. 3 c depictshow the tunnel 320 can be measured using a measurement gauge 322 insidethe bone joint 304. As shown in FIG. 3 c , the measurement gauge 322 canbe held against the bone joint 304 during the retro-reaming operation.Further tunnel measurement options include (1) using the measurementgauge 322 on the outside of the bone joint 304 to visualize the reamermarkings, (2) leaving only the bullet 308 in place while measuring thetunnel 320, (3) leaving both the bullet 308 and the guide 310 in placewhile measuring the tunnel 320, and (4) using, on the outside of the 4.5mm reamer 312, a measurement sleeve 324 (see FIG. 3 c ) that is manuallyheld against the bone joint 304.

In a second illustrative example, as described with reference to steps1-4 of FIG. 4 , a 4.5 mm reamer 402 is employed as a retro-reaminginstrument. As depicted in step 1 (see FIG. 4 ), a 2.4 mm guide wire 404is drilled into a bone joint 406 using a suitable drill 408, bullets410, 412, and guide 414. As depicted in step 2, the internal 2.4 mmbullet 410 is removed. As depicted in step 3, the 4.5 mm reamer 402 isoperated, using the drill 408, to drill a tunnel, from the outside in,over the guide wire 404 through the larger bullet 412 with the guide 414in place. As depicted in step 4, the 4.5 mm retro-reaming instrument 402is used to retro-ream a tunnel 416 through the bone joint 406. Withreference to this second illustrative example, the 4.5 mm retro-reaminginstrument 402 can be self-actuating. Alternatively, a 2.4 mm actuatorrod can be employed to actuate the 4.5 mm retro-reaming instrument 402to retro-ream the tunnel 416 through the bone joint 406.

In a third illustrative example, as described with reference to steps1-2 of FIG. 5 , a 4.5 mm reamer 502 is employed as the bullet for aguide wire 504. As depicted in step 1 (see FIG. 5 ), using a suitabledrill 506 and guide 508, the guide wire 504 is inserted in a bone joint510 through the combined bullet/4.5 mm reamer 502. As depicted in step2, the drill 506 is engaged with the combined bullet/4.5 mm reamer 502,and a 4.5 mm tunnel 512 is reamed through the bone joint 510. In effect,the bullet becomes the 4.5 mm reamer 502. Allowing the 4.5 mm reamer 502to serve as the bullet reduces the need to remove the bullet afterdrilling the guide wire 504. It is noted that a holder for the bulletmay be configured to allow lateral removal of the guide 508.

FIG. 6 depicts a plurality of alternative embodiments 700, 800, 900,1000, 1100, 1200, 1300, 1400 of the disclosed retrograde reamer. Asshown in FIGS. 7 a and 7 b , the retrograde reamer 700 includes one ormore blades 702, one or more wedge members 704, and one or more flexmembers 706. During use, the guide wire is typically removed from thesurgical site, and the blades 702 connected to the respective flexmembers 706 are inserted into a tubular shaft 701 of, for example, a 4.5mm reamer, thereby causing the blades 702 to impinge against therespective wedge members 704 and move in a radial fashion out of theshaft 701 through corresponding slots 708 in the shaft 701. In someembodiments, the shaft 701 can have a stepped internal diameter.Further, in some embodiments, the flex members 706 can be implemented ashinges. The blades 702 connected to the respective flex members 706 canbe advanced through the tubular shaft 701 to deploy the blades 702, andsubsequently retracted into the shaft 701 to close or collapse theblades 702. The diameters of tunnels created using the retrograde reamer700 are adjustable based on how far the wedge members 704 drive theblades 702 through the respective slots 708 in the shaft 701.Alternatively, the diameters of tunnels created using the alternativeconfiguration 700 can be fixed. It is noted that the retrograde reamer700 can be keyed to fenestrations of the 4.5 mm reamer.

FIGS. 8 a and 8 b depict detailed views of the alternative configuration800 of the retrograde reamer. As shown in FIGS. 8 a and 8 b , theretrograde reamer 800 includes a shaft 803, and one or more blades 802connected by a pivot 805 to a distal end of the shaft 803. In someembodiments, the shaft 803 can have a reamer tooth 810 at its distalend. During use, the guide wire is typically removed from the surgicalsite, and the shaft 803 and blades 802 are inserted into a tubular shaft801 of, for example, a 4.5 mm reamer. In this case, the blades 802 canbe keyed to support slots 808 in the shaft 801. To deploy the blades802, the pivot 805 is advanced past a distal end of the shaft 801 (seedirectional arrow 812), a toggling mechanism pivotably places the blades802 in a cutting position (see directional arrow 814), and the shaft 803is rotated, for example, by a quarter turn (see directional arrow 818),and then retracted into the shaft 801 to place the blades 802 into thecorresponding support slots 808 (see directional arrow 816). To close orcollapse the blades 802, the pivot 805 is advanced past the distal endof the tubular shaft 801 (see directional arrow 812) to pivotally placethe blades 802 along the longitudinal axis of the shaft 803, and theshaft 803 is rotated by a quarter turn (see directional arrow 818) andthen retracted back into the shaft 801 (see directional arrow 816). Insome embodiments, the retrograde reamer 800 can include a single-sidedblade (L-shaped blade configuration), or double-sided blades (T-shapedblade configuration). The diameters of tunnels created using theL-shaped or T-shaped blade configuration are typically fixed. It isnoted that the L-shaped blade configuration generally requires lesspenetration into a bone joint space for deployment. It is further notedthat the toggle mechanism for deploying the blades 802 can beimplemented using torsion springs, pull wires, a push rod, a springplunger, or any other suitable toggle mechanism.

FIGS. 9 a and 9 b depict detailed views of the alternative configuration900 of the retrograde reamer. As shown in FIGS. 9 a and 9 b , theretrograde reamer 900 includes an internal shaft 903, a tubular externalshaft 905, and one or more blades 902. In some embodiments, the distalend of the external shaft 905 can have a pointed or sharpened tip.During use, the external shaft 905 can function as a guide wire. Todeploy the blades 902, the internal shaft 903 is retracted into thetubular shaft 905 (see directional arrow 912), causing the blades 902 todeploy through corresponding slots 909 in the shafts 903, 905, as wellas through corresponding slots 908 in a tubular shaft 901 of, forexample, a 4.5 mm reamer. To collapse the blades 902, the internal shaft903 is advanced into the tubular shaft 905. In some embodiments, theretrograde reamer 900 includes a single blade. The diameters of tunnelscreated using the blades 902 are typically fixed. It is noted that themechanism for deploying the blades 902 can be implemented using torsionsprings, pull wires, a push rod, a spring plunger, or any other suitablemechanism. It is further noted that the retrograde reamer 900 can bekeyed to fenestrations of the 4.5 mm reamer.

FIGS. 10 a and 10 b depict detailed views of the alternativeconfiguration 1000 of the retrograde reamer. As shown in FIGS. 10 a and10 b , the retrograde reamer 1000 includes a shaft 1005 having apivotable distal end 1007 with a pointed or sharpened tip. During use,the guide wire is typically removed from the surgical site, and theshaft 1005 is inserted into a tubular shaft 1001 of, for example, a 4.5mm reamer. To deploy the pointed or sharpened tip of the pivotabledistal end 1007, the distal end 1007 of the shaft 1005 is advanced pasta distal end of the 4.5 mm reamer (see directional arrow 1012), thedistal end 1007 is rotated up to 180° at a pivotable joint to a cuttingposition (see directional arrow 1014), and the shaft 1005 is retractedto place the distal end 1007 into a support slot 1009 in the shaft 1001(see directional arrow 1016). To close or collapse the pointed orsharpened tip of the pivotable distal end 1007, the shaft 1005 isadvanced past the distal end of the 4.5 mm reamer (see directional arrow1012), the distal end 1007 is rotated to pivotally place the distal end1007 along the longitudinal axis of the shaft 1005, and the shaft 1005is retracted back into the tubular shaft 1001 (see directional arrow1016). The diameters of tunnels created using the pivotable distal end1007 are typically fixed. It is noted that the mechanism for deployingthe pivotable distal end 1007 can be implemented using a torsion coil1004, a laser cut hypotube, a micro-universal joint, or any othersuitable mechanism. In some embodiments, the shaft 1005 can function asthe guide wire. In addition, in some embodiments, the pivotable joint ofthe pivotable distal end 1007 can have more than one seating position.

FIGS. 11 a and 11 b depict detailed views of the alternativeconfiguration 1100 of the retrograde reamer. As shown in FIGS. 11 a and11 b , the retrograde reamer 1100 includes a shaft 1105 having a distalend with a pointed or sharpened tip, and one or more blades 1106attached to one or more flex members 1104. For example, the flex members1104 can be made from a Nitinol alloy, or any other suitable material.During use, the shaft 1105 and blades 1106 are inserted into a tubularshaft 1101 of, for example, a 4.5 mm reamer. To deploy the blades 1106,the shaft 1105 is rotated to position the blades 1106 in registrationwith slots 1109 in the shaft 1101 (see directional arrow 1112), and thenadvanced to move the blades 1106 attached by the flex member 1104through the slots 1109 (see directional arrows 1114). To close orcollapse the blades 1106, the shaft 1105 is retracted, closing orcollapsing the blades 1106 within the shaft 1101, and then rotated tomove the blades 1106 away from the slots 1109. In some embodiments, theNitinol alloy can be employed as the cutting member. The diameters oftunnels created using the alternative configuration 1100 are adjustablebased on how far the blades 1106 are deployed through the slots 1109.Alternatively, the diameters of tunnels created using the alternativeconfiguration 1100 can be fixed.

FIGS. 12 a and 12 b depict detailed views of the alternativeconfiguration 1200 of the retrograde reamer. As shown in FIGS. 12 a and12 b , the retrograde reamer 1200 includes a shaft 1205 having a distalend with a pointed or sharpened tip, and one or more blades 1206attached to a sidewall of a tubular shaft 1201 (e.g., a 4.5 mm reamer)by one or more flex members 1209. During use, the shaft 1205 is insertedinto the tubular shaft 1201 of the 4.5 mm reamer. To deploy the blades1206, the shaft 1205 is retracted through the tubular shaft 1201, and adeployment member such as a wire 1207 (e.g., a flat wire or rod)connected to the blade 1206 is pulled to deploy the blade 1206 through aslot 1211 in the shaft 1201 (see directional arrow 1212). To close orcollapse the blades 1206, the shaft 1205 is advanced into the tubularshaft 1201, impinging against the blade 1206 and closing or collapsingthe blade 1206 within the shaft 1201. The diameters of tunnels createdusing the retrograde reamer 1200 can be adjustable based on how far thewire 1207 deploys the blade 1206 through the slot 1211 in the shaft1201. Alternatively, the diameters of tunnels created using theretrograde reamer 1200 can be fixed. It is noted that the retrogradereamer 1200 of the retrograde reamer can be keyed to fenestrations ofthe 4.5 mm reamer.

FIGS. 13 a and 13 b depict detailed views of the alternativeconfiguration 1300 of the retrograde reamer. As shown in FIGS. 13 a and13 b , the retrograde reamer 1300 includes a shaft 1305 having a distalend with a pointed or sharpened tip, and one or more blades 1306rotatably attached to a tubular inner shaft 1303 of, for example, a 4.5mm reamer. During use, the shaft 1305 is initially inserted into theinner shaft 1303, which is disposed within a tubular outer shaft 1301 ofthe 4.5 mm reamer. To deploy the blades 1306, the shaft 1305 isretracted through the inner shaft 1303, the outer shaft 1301 is rotatedto disengage the blades 1306 from the shaft 1301 (see directional arrow1312), and the outer shaft 1301 is advanced to rotatably position theblades 1306 substantially perpendicular to the respective shafts 1301,1303 (see directional arrow 1314). To close or collapse the blades 1306,the outer shaft 1301 is retracted to allow the blades 1306 to rotateback against the inner shaft 1303, and the shaft 1305 is advanced intothe tubular inner shaft 1303 to maintain the blades 1306 against theshaft 1303. The diameters of tunnels created using the retrograde reamer1300 can be fixed.

FIG. 14 depicts a detailed view of the alternative configuration 1400 ofthe retrograde reamer. As shown in FIG. 14 , the retrograde reamer 1400includes a shaft 1407 having a distal end with a pointed or sharpenedtip, and one or more helical blades 1406 (e.g., single or double helix,or interlocking helix members) attached to a tubular outer shaft 1401of, for example, a 4.5 mm reamer, which also has a tubular inner shaft1405. During use, the shaft 1407 is inserted into the tubular innershaft 1405. To deploy the helical blades 1406, the tubular outer shaft1401 is rotated (see directional arrow 1414) and advanced (seedirectional arrow 1412) to unwind the helical blades 1406 away from theinner shaft 1405, thereby forming an adjustable cutting diameter. Toclose or collapse the helical blades 1406, the outer shaft 1401 isrotated in the opposite direction and retracted to wind the helicalblades 1406 back against the inner shaft 1405. The diameters of tunnelscreated using the retrograde reamer 1400 are adjustable based on how farthe helical blades 1406 are deployed to form the cutting diameter.Alternatively, the diameters of tunnels created using the retrogradereamer 1400 can be fixed.

FIGS. 15 a-15 c depict a further alternative embodiment 1500 of thedisclosed retrograde reamer. The retrograde reamer 1500 is an expandablereamer that can be used to perform an anterior cruciate ligament (ACL)repair or reconstruction using the outside in technique. Further, theretrograde reamer 1500 can interface with a suitable aimer to assist thesurgeon in the proper placement of the femoral tunnel.

In some embodiments, the retrograde reamer 1500 is cannulated to allowthe surgeon to use a standard 2.4 mm guide wire to place the tunnel. Asshown in FIGS. 15 a-15 c , the retrograde reamer 1500 includes a mainshaft 1504, an outer sleeve 1502, and a plurality of cutting members1506 (e.g., two (2) cutting members). The cutting members 1506 arecontained within the main shaft 1504, and swing outward upon activationof the outer sleeve 1502. The outer sleeve 1502 has windows that allowthe respective cutting members 1506 to pass therethrough. The cuttingmembers 1506 move via a rotation about a guide pin 1508. The cuttingmembers 1506 have a cam profile to ensure that, while the outer sleeve1502 applies axial force, the cutting members 1506 swing outward. FIGS.15 a and 15 b depict the retrograde reamer 1500 in a closed or collapsedconfiguration and an open configuration, respectively.

FIG. 15 c depicts the open configuration of the retrograde reamer 1500in greater detail. The retrograde reamer 1500 allows the use of astandard 2.4 mm guide pin. Further, the outer sleeve 1502 is configuredto deploy and retract the cutting members 1506. Moreover, the retrogradereamer 1500 can be cannulated to allow deployment and drilling over aguide wire. The cutting members 1506 can also be changed to accommodateall desired sizes (e.g., 6 mm to 13 mm). Advantages of the retrogradereamer 1500 include its capability to have a cannulated configuration,the integral configuration of the cutting members 1506, its capabilityto be powered via a suitable drill, and its capability to be configuredwith the dual cutting members 1506, which may allow more accurate tunnelformation.

In an exemplary mode of operation, the guide pin 1508 (e.g., a 2.4 mmguide pin) can be drilled using a suitable aimer. Using the retrogradereamer 1500 in the closed or collapsed configuration (see FIG. 15 a ), atunnel (e.g., a 4.5 mm tunnel) can then be drilled, from the outside in,through bone into the space of a bone joint. Next, the cutting members1506 can be activated and deployed by moving the outer sleeve 1502relative to the main shaft 1504, thereby causing the cutting members1506 to pass through the windows in the outer sleeve 1502. A tunnelhaving a desired diameter and depth can then be drilled through the bonein a retrograde fashion, using the cutting members 1506 in theirdeployed positions. The outer sleeve 1502 and main shaft 1504 can thenbe advanced back into the space of the bone joint, allowing the cuttingmembers 1506 to be retracted within the main shaft 1504. Finally, theouter sleeve 1502, the main shaft 1504, as well as the cutting members1506 in their retracted or collapsed positions, can be removed from thesurgical site.

Having described the above illustrative embodiments, furthermodifications to and/or variations of the disclosed surgical instrumentmay be made, as described below with reference to the followingexamples. Example 1 is a retrograde reamer for use in surgicalprocedures that includes a first tubular shaft, at least one secondshaft movably disposable within the first tubular shaft, and at leastone cutting member movably coupled to one of the first tubular shaft andthe second shaft. In response to relative movement of the first tubularshaft and the second shaft, the cutting member is adapted to bedisplaced from a collapsed position to at least one deployed position,thereby defining at least one cutting diameter.

In Example 2, the subject matter of Example 1 can optionally includefeatures wherein the cutting member is movably coupled to the firsttubular shaft.

In Example 3, the subject matter of any one of Examples 1-2 canoptionally include features wherein the cutting member is disposedadjacent a distal end of the first tubular shaft, and wherein, inresponse to relative rotational movement of the first tubular shaft andthe second shaft, an externally threaded portion at a distal end of thesecond shaft is operative to threadingly engage an internally threadedportion at the distal end of the first tubular shaft, thereby causingthe distal end of the first tubular shaft to axially move in a proximaldirection, and the cutting member to be displaced from the collapsedposition to the deployed position.

In Example 4, the subject matter of any one of Examples 1-2 canoptionally include features wherein the cutting member includes one ormore helical blades, and wherein, in response to relative rotational andaxial movement of the first tubular shaft and the second shaft, thehelical blades are operative to unwind from the second shaft, therebydisplacing the helical blades from the collapsed position to thedeployed position.

In Example 5, the subject matter of any one of Examples 1-2 canoptionally include features wherein the first tubular shaft has asidewall, the sidewall including at least one opening therethrough, andwherein the retrograde reamer further includes a flex member operativeto movably couple the cutting member to the sidewall of the firsttubular shaft substantially opposite the opening in the sidewall, and adeployment member coupled to the cutting member. The deployment memberis operative, in response to being pulled distally, to displace thecutting member in a radial fashion from the collapsed position to thedeployed position, such that the cutting member passes at leastpartially through the opening in the sidewall of the first tubular shaftwhile being displaced to the deployed position.

In Example 6, the subject matter of Example 1 can optionally includefeatures wherein the cutting member is movably coupled to the secondshaft.

In Example 7, the subject matter of any one of Examples 1 and 6 canoptionally include features wherein, in response to relative axialmovement of the first tubular shaft and the second shaft, the cuttingmember is operative to be displaced from the collapsed position to thedeployed position.

In Example 8, the subject matter of any one of Examples 1, 6, and 7 canoptionally include at least one wedge member disposed within the firsttubular shaft adjacent a distal end of the first tubular shaft, and atleast one flex member adapted to movably couple the cutting member tothe second shaft. In response to relative axial movement of the firsttubular shaft and the second shaft, the cutting member is operative toimpinge against the wedge member, thereby causing the flex member to bedisplaced from a first position substantially parallel to a longitudinalaxis of the second shaft to a second off-axis position, and the cuttingmember to be displaced from the collapsed position to the deployedposition.

In Example 9, the subject matter of Example 8 can optionally includefeatures wherein the first tubular shaft has a sidewall with at leastone opening formed therethrough, and wherein, in response to thedisplacement of the flex member, the cutting member is operative to bedisplaced in a radial fashion from the collapsed position to thedeployed position, the cutting member passing at least partially throughthe opening in the sidewall of the first tubular shaft while beingdisplaced to the deployed position.

In Example 10, the subject matter of any one of Examples 1 and 6 canoptionally include features wherein the cutting member is movablycoupled at a distal end of the second shaft by a pivot pin.

In Example 11, the subject matter of Example 10 can optionally includefeatures wherein, in response to axial movement of the second shaft in adistal direction, the cutting member is operative to move distally andto rotate about the pivot pin, thereby displacing the cutting memberfrom the collapsed position to the deployed position.

In Example 12, the subject matter of any one of Examples 1, 6, 10, and11 can optionally include features wherein the first tubular shaft has asidewall with at least one slot formed therethrough, and wherein, inresponse to axial movement of the second shaft in a proximal direction,the cutting member is operative to move proximally, thereby causing thecutting member to be placed in the slot in the deployed position.

In Example 13, the subject matter of any one of Examples 1 and 6 canoptionally include features wherein the at least one second shaftincludes a second tubular shaft, and an internal shaft disposed withinthe second tubular shaft.

In Example 14, the subject matter of Example 13 can optionally includefeatures wherein the first tubular shaft, the second tubular shaft, andthe internal shaft each have a sidewall including at least one openingformed therethrough, and wherein, in response to relative axial movementof the second tubular shaft and the internal shaft, the cutting memberis operative to be displaced from the collapsed position to the deployedposition, the cutting member passing at least partially throughrespective sidewall openings of the first tubular shaft, the secondtubular shaft, and the internal shaft while being displaced to thedeployed position.

In Example 15, the subject matter of any one of Examples 1 and 6 canoptionally include features wherein the cutting member is adapted tocorrespond to a pivotable distal end of the second shaft.

In Example 16, the subject matter of Example 15 can optionally includefeatures wherein, in response to axial movement of the second shaft in adistal direction, the pivotable distal end of the second shaft isoperative to rotate, at a pivotable joint, from the collapsed positionto the deployed position.

In Example 17, the subject matter of any one of Examples 15-16 canoptionally include features wherein the first tubular shaft has asidewall including at least one slot formed therethrough, and wherein,in response to axial movement of the second shaft in a proximaldirection, the pivotable distal end of the second shaft is operative tomove proximally, thereby causing the pivotable distal end to be placedin the slot in the deployed position.

In Example 18, the subject matter of any one of Examples 1 and 6 canoptionally include features wherein the cutting member has a firstcutting member portion and a second cutting member portion, and a flexmember interconnecting the first and second cutting member portions.

In Example 19, the subject matter of Example 18 can optionally includefeatures wherein the first tubular shaft has a sidewall including atleast one opening formed therethrough, and wherein, in response to axialmovement of the second shaft toward a distal end of the first tubularshaft, the flex member is operative to allow the first and secondcutting member portions to be displaced from the collapsed position tothe deployed position, the first and second cutting member portionspassing at least partially through the sidewall opening of the firsttubular shaft while being displaced to the deployed position.

In Example 20, the subject matter of any one of Examples 1 and 6 canoptionally include features wherein the cutting member is adapted, inthe collapsed position, to be selectively engaged with and disengagedfrom the first tubular shaft, and wherein, in response to relativerotational movement of the first tubular shaft and the second shaft, thecutting member is operative to be disengaged from the first tubularshaft, and to be displaced from the collapsed position to the deployedposition.

Example 21 is a method of operating a retrograde reamer in a surgicalprocedure that includes providing a retrograde reamer, the retrogradereamer including a first tubular shaft, at least one second shaftmovably disposable within the first tubular shaft, and at least onecutting member movably coupled to one of the first tubular shaft and thesecond shaft, performing relative movement of the first tubular shaftand the second shaft, and, in response to the relative movement of thefirst tubular shaft and the second shaft, displacing the cutting memberfrom a collapsed position to at least one deployed position, therebydefining at least one cutting diameter.

In Example 22, the subject matter of Example 21 can optionally includefeatures wherein the performing of relative movement of the firsttubular shaft and the second shaft includes performing relativerotational movement of the first tubular shaft and the second shaft.

In Example 23, the subject matter of any one of Examples 21-22 canoptionally include features wherein the performing of relative movementof the first tubular shaft and the second shaft includes performingrelative axial movement of the first tubular shaft and the second shaft.

In Example 24, the subject matter of any one of Examples 21-23 canoptionally include features wherein the performing of relative movementof the first tubular shaft and the second shaft includes performingrelative rotational and axial movement of the first tubular shaft andthe second shaft.

In Example 25, the subject matter of any one of Examples 21-24 canoptionally include features wherein the retrograde reamer furtherincludes a flex member movably coupling the cutting member to a sidewallof the first tubular shaft at a location substantially opposite anopening in the sidewall, and a deployment member coupled to the cuttingmember, and wherein the method further includes pulling the deploymentmember distally, and, in response to the deployment member being pulleddistally, displacing the cutting member in a radial fashion from thecollapsed position to the deployed position, the cutting member passingat least partially through the opening in the sidewall of the firsttubular shaft while being displaced to the deployed position.

It will be appreciated by those of ordinary skill in the art that stillfurther modifications to and variations of the disclosed surgicalinstrument may be made without departing from the inventive conceptsdisclosed herein. Accordingly, the invention should not be viewed aslimited except as by the scope and spirit of the appended claims.

1-25. (canceled)
 26. A method of drilling a bone tunnel, comprising:introducing a retrograde reamer into a surgical site, the retrogradereamer comprising: a first tubular shaft having a proximal end, a distalend, and a longitudinal axis extending therebetween; a second tubularshaft moveably disposed about the proximal end of the first tubularshaft; and at least one cutting member having a proximal end and adistal end, the distal end of the at least one cutting member pivotablycoupled to the distal end of the first tubular shaft, the at least onecutting member having an arcuate shape to conform to an outer surface ofthe first tubular shaft in a closed position such that an outer surfaceof the at least one cutting member extends in-line with an outer surfaceof the second tubular shaft; moving the second tubular shaft relative tothe first tubular shaft; and in response to the movement of the secondtubular shaft relative to the first tubular shaft, displacing thecutting member from a closed position to an open position, therebydefining at least one cutting diameter.
 27. The method of claim 26,wherein moving the second tubular shaft relative to the first tubularshaft comprises rotating the second tubular shaft relative to the firsttubular shaft.
 28. The method of claim 26, wherein moving the secondtubular shaft relative to the first tubular shaft comprises axiallymoving the second tubular shaft relative to the first tubular shaft. 29.The method of claim 26, wherein the first tubular shaft is a 4.5 mmreamer.
 30. The method of claim 26, further comprising drilling a firsttunnel in bone with the distal end of the first tubular shaft in a firstdirection with the at least one cutting member in the closed position.31. The method of claim 30, further comprising overdrilling a secondtunnel within the first tunnel in the bone in a second directionopposite the first direction with the at least one cutting member in theopen position.
 32. The method of claim 26, wherein introducing theretrograde reamer into the surgical site comprises disposing the firsttubular member over a guide wire.
 33. The method of claim 26, wherein,prior to displacing the cutting member from a closed position to an openposition, removing the guide wire from the first tubular member.
 34. Themethod of claim 26, wherein the at least one cutting member is twocutting members.
 35. The method of claim 26, wherein the cuttingdiameter is between about 6 mm and 13 mm.
 36. The method of claim 26,further comprising disposing the first tubular shaft over a guidewire.